Transparent liquid for encapsulated drug delivery

ABSTRACT

There is provided a stable transparent multi-component composition useful for the delivery of water soluble active agents to animals. The compositions are formulated with a mixture of an oil phase, an aqueous phase, and a surfactant system, along with the active agent to be delivered to the animal. The compositions are specially formulated to be compatible with capsules such as gelatin and starch capsules. The aqueous phase of the compositions contains a substantial amount of polyethylene glycol and can optionally also contain a plasticizer. Preferred active agents are proteinaceous materials.

This is a continuation-in-part of application Ser. No. 08/153,846 filedNov. 17, 1993, now abandoned, which is incorporated herein in itsentirety.

FIELD OF INVENTION

This invention relates to compositions useful in the delivery ofbiologically active agents, and methods of making and using the same.More particularly, it relates to certain unique formulationsadvantageously formulated to enhance delivery of such biologicallyactive agents as drugs, proteins, and polypeptides, includingtherapeutically-active ones used as medicaments, in capsules designedprimarily for oral administration.

BACKGROUND OF THE INVENTION

There is a continuing need for new and improved delivery systems forbiologically active materials. Many of the therapeutic agents emergingfrom the biotechnology revolution, as well as some older drugs such asinsulin and calcitonin, consist of small and large molecule proteins.These drugs must now be injected into the patient because they areunable to survive the digestive process and do not readily pass throughthe mucosal lining of the gastrointestinal tract and enter thebloodstream. A new drug delivery system that would enable proteins toenter the bloodstream through, for example, the lining of the digestivesystem would be of great benefit.

Improved drug delivery systems could also provide much improvedconvenience for patients. For example, calcitonin is a generic peptidehormone used for treatment of osteoporosis and other diseases involvingbone loss. Osteoporosis affects 24 million Americans, including 2/3 ofthe women past menopause. Currently, most calcitonin is delivered byinjection. Calcitonin treatment for osteoporosis requires long-termadministration with low but frequent doses of the drug. An oral orsuppository formulation of calcitonin would offer great advantages topatients undergoing such treatments.

Recently, thermodynamically stable compositions, such as microemulsions,micelies, and liposomes, have been used in an attempt to formulate oraldrug delivery systems for proteinaceous materials. Microemulsions areknown in the art as thermodynamically stable compositions of an oil,surfactant, and aqueous component which when admixed form a stable,transparent solution having a particle size of below about 200 nm andgenerally greater than about 5-10 nm. The microemulsions are stable inthat they do not break upon standing into normal emulsions, as doemulsions made to have particle sizes below about 200 nm by the use ofhigh shear mixing devices. Microemulsions are further described byScience, Kahlweit, 248, 617-621 (1988) and in Bhargava et al., Pharm.Tech., 46-53 (March 1987), both of which are incorporated herein intheir entirety by reference.

Water-in-oil (w/o) microemulsions are those microemulsions in which theaqueous phase is the internal phase. The w/o microemulsions can bedetermined by such tests as dye solubility and conductivity analysis.The w/o microemulsions generally will not initially disperse a watersoluble dye. The w/o microemulsions also have a low conductivity ofelectricity.

Micellar solutions are in some respects similar to microemulsions,however they generally have a smaller particle size. The surfactantsmolecules assemble through cooperative association in the water to formaggregates called micelies. These micelles can solubilize an oilcomponent, but generally not to the extent of a microemulsion. The term"swollen micelles" is sometimes used to refer to micellar solutionscontaining an oil component.

The aim of such compositions is to solubilize the proteinaceous materialin an aqeuous component and to provide for the storage of theproteinaceous material while maintaining the bioavailability of thematerial.

Various active agents, especially proteins and peptides, must beadministered to the intestinal region for proper uptake of the agent bythe body. The bioavailability of these drug agents is commonly decreasedupon exposure of the drug to conditions in the stomach. Therefore, thedrug delivery composition is generally administered in an entericallycoated capsule. Problems arise in formulating a drug deliverycomposition that can maintain the bioavailability of the drug within theconfines of such a capsule and which can also enhance the delivery ofthe drug upon administration. Typically, the chemical compositions ofthe drug delivery composition and the capsule are thermodynamicallyincompatible in that mass transfer of hydrophilic materials occurs whichdisrupts the structural integrity of the capsule and the stability ofthe composition.

Water-in-oil microemulsion formulations for the delivery of biologicallyactive materials including proteins and peptides are shown in commonlyassigned co-pending application Ser. No. 07/885,202, which is hereinincorporated by reference in its entirety. The formulation of themicroemulsion systems into capsules, and preferably enterically coatedcapsules, is shown for the delivery of the active agent tothe/intestines. However, it has been found that in certain embodiments,mass transfer can occur between the aqueous phase of the microemulsionsand the capsule which can lead to the degradation of the capsule andmicroemulsion composition.

A composition that contains agents stated to form a microemulsion in thegastrointestinal tract is disclosed in U.S. Pat. No. 5,206,219 to Desai.The compositions of Desai require the presence of cholesterol and aphospholipid. The water content of the compositions is maintained below5% w/w and such polyol co-solvents as propylene glycol and polyethyleneglycol are included as hydrophilic materials. The requirement of thepresence of the cholesterol and phospholipid unduly restricts theformulation of a drug delivery system.

A need therefore exists to formulate a drug delivery composition, usefulfor the delivery of such active agents as proteins and peptides, thatcan be prepared and stored within a capsule while maintaining thestability of the system and the bioavailability of the active agent.

SUMMARY OF THE INVENTION

Drug delivery compositions are provided herein which contain an oilphase, an aqueous phase, a surfactant or mixture thereof, and atherapuetic, preferably proteinaceous, active agent. The drug deliverycomposition is a transparent composition and is thermodynamicallystable. Such a drug delivery composition is suitable for storage andadministration of the active agent, preferably by an oral route.

The drug delivery compositions are specifically formulated to becompatible with capsules. Thus, the compositions exhibit excellentstorage stability in a capsule form. The compositions contain an aqueousphase containing a major amount of polyethylene glycol and a minoramount of water either alone or in admixture with a plasticizer. Suchformulations are vastly superior in the capsule form to correspondingw/o microemulsion formulations having major amounts of water in theaqueous phase.

The drug delivery compositions are distinguished from those oralmulti-component drug delivery compositions which are formulated to forma microemulsion in situ in the intestine in that they do not require thepresence of a phospholipid in conjunction with a cholesterol component.

BRIEF DESCRIPTION OF THE DRAWINGS

Compositions of the present invention are graphically depicted in FIGS.1-5. Apex A represents 100 wt. % of the aqueous phase, apex B represents100 wt. % of the oil phase, and apex C represents 100 wt. % of thesurfactant and permeation enhancers. The shaded area representscompositions that produce transparent solutions. All parts are on aweight basis.

FIG. 1 is a phase diagram wherein the aqueous phase constituted 8.6parts PEG 600, 1 part water, and 0.4 parts sorbitol. The oil phaseconstituted Captex 200 and the surfactant phase constituted 6 partsImwitor 308 and 4 parts Tween 80.

FIG. 2 is a phase diagram wherein the aqueous phase constituted 8.6parts PEG 300, 1 part water, and 0.4 parts sorbitol. The oil phaseconstituted Captex 200 and the surfactant phase constituted 6 partsImwitor 308 and 4 parts Tween 80.

FIG. 3 is a phase diagram wherein the aqueous phase constituted 8.6parts PEG 400, 1 part water, and 0.4 parts sorbitol. The oil phaseconstituted Captex 200 and the surfactant phase constituted 6 partsImwitor 308 and 4 parts Tween 80.

FIG. 4 is a phase diagram wherein the aqueous phase constituted 8.6parts PEG 400, 1 part water, and 0.4 parts sorbitol. The oil phaseconstituted Captex 200 and the surfactant phase constituted 4 partsImwitor 308 and 6 parts Tween 80.

FIG. 5 is a phase diagrams wherein the aqueous phase constituted 8.0parts PEG 400, 1 part water, and 1.0 parts sorbitol. The oil phaseconstituted Captex 200 and the surfactant phase constituted 6 partsImwitor 308 and 4 parts Tween 80.

DESCRIPTION OF THE INVENTION

Drug delivery compositions are described herein which contain an oil orlipid (hydrophobic) phase, an aqueous (hydrophilic) phase, and asurfactant or mixture of surfactants, and an active agent, preferablybiologically active, more preferably a therapeutic, proteinaceous activeagent. The drug delivery compositions are optimized for use inconjunction with capsules for oral, rectal, and vaginal, preferably oraland rectal, and more preferably oral, administration. However, thecompositions of this invention can be administered by any method such asparentoral, enteral, and any other mucousal means and without a capsulecontainer.

The present invention provides for the transparent solutions with andwithout the active agent. The compositions formulated without the activeagent are generally referred to as delivery compositions, and with theactive agent is generally referred to as drug delivery compositions. Thedelivery compositions have various uses, but are primarily useful aspharmaceutical compositions into which an active agent, such as thosedefined in this invention, can be incorporated.

The delivery compositions have been designed to be compatible with acapsule container by formulating the components of the aqueous phase tocontain a major amount of polyethylene glycol (PEG) and a minor amountof water or saline. The ratio of PEG to water is altered in accordancewith the composition of the capsule material to optimize the stabilitybetween the delivery composition and the capsule composition. In such away, the mass transfer between the capsule and the delivery compositionis decreased resulting in a more stable overall formulation.

The present delivery compositions are described as multi-componentsystems. The delivery compositions of the present invention arepreferably transparent, thermodynamically stable solutions resemblingswollen micelles and w/o microemulsions, however the particle size ofthe present compositions may not fall within the ranges commonlyunderstood to encompass micelles and microemulsions. Generally, theparticle sizes for the inventive compositions are below about 15 nm,preferably below about 10 nm, and more preferably below about 5 nm, andthus the compositions can also be referred to as solutions.

The delivery compositions can be formulated with any of the followingranges of oils, aqueous phase components, and surfactants. Thecompositions can be prepared without the need for a mixture of aphospholipid and cholesterol component.

The oil phase of the delivery compositions contains at least one oilcomponent. The oil component is generally any such known oil accepted inthe food or pharmaceutical industry. The oil, or mixtures thereof, maybe liquid at room temperature, although in some cases, mild heating of asolid oil to form a liquid is acceptable. Heating of an oil that issolid at room temperature is desirable for formulations intended assuppositories, creams, salves, and in some cases as oral capsules.

Illustrations of suitable oils for purposes of this invention includetriesters of glycerol having from about 9 to 83, preferably 21-60, andmore preferably 21-45 carbon atoms. The triglycerides are furtherdefined as short chain triglycerides having 9-15 carbon atoms, mediumchain triglycerides having 21-45 carbon atoms, and long chaintriglycerides having above 45 carbon atoms. Medium chain triglyceridesare preferred. Examples of glycerol triesters include natural, edibleoils such as canola, corn, olive, sunflower and coconut oils, triacetin,the decanoic acid esters, and chemically-synthesized oils such as1-oleyl-2,3-diacetyl glycerol. Commercially available triglyceride oils,both natural and chemically-synthesized, are available from KarlshamnsLipid Specialties, U.S.A. as the Captex® series, and from Huls AmericaInc. as the Miglyol series.

Other suitable oils include diesters of propylene glycol having fromabout 7 to 55, preferably 15-40 carbon atoms, more preferably propyleneglycol esters of capric and caprlic acids, and mixtures thereof, havingfrom 19 to 23 carbon atoms. The diesters of propylene glycols arefurther defined as short chain having from 7-11 carbon atoms, mediumchain having from 15-31 carbon atoms, and long chain having above 31carbon atoms. Preferred propylene glycol diesters are the medium chainoils. Diesters of propylene glycols include propylene glycol esters ofcapric acid, caprylic acid, and mixtures thereof such as Captex® 200,and Captex® 800 (Karlshamns Lipid Specialities, Columbus, Ohio) andother ester groups as described above for glycerol.

The oils can be of natural or synthetic origin and can contain fattyacids of different lengths within their structure. Other lipophilic oilcomponents can also be used in the oil phase such as fish oil productsand mineral oil products. Other lipophilic materials that function as anoil phase are also encompassed by this invention. Such oil componentsare preferably food or pharmaceutical grade quality.

The oil phase is present in the delivery compositions from about 1 toabout 80, preferably from about 5 to about 70, and more preferably from8 to 50 weight percent. This weight percent basis is based on the totalweight of the components which make up the transparent deliverycomposition, that is, the oil phase components, the aqueous phasecomponents, and the surfactant components, without the active agent oroptional additives such as the antioxidants, preservatives, etc.

The delivery compositions of the present invention are created by theinterplay between the surfactant or mixture of surfactants (the"surfactant component") and the oil and aqueous phase components. Thesurfactant component can be described by its hydrophilic-lipophilicbalance (HLB) which is an empirical quantity, on an arbitrary scale,which is a measure of the polarity of a surfactant or mixture ofsurfactants. See P. Becher et al., "Nonionic Surfactant, PhysicalChemistry," Marcel Dekker, New York (1987), pages 439-456. It is awidely known and used term.

The delivery compositions of the present invention can be prepared witheither a single surfactant or a mixture of surfactants. The final HLB ofthe composition is generally at least about 5, preferably from about 5to about 15. The compositions are preferably prepared with a mixture ofsurfactants to allow for versatility, greater stabity, and enhanced drugadsorption. The surfactant component generally contains at least one lowHLB surfactant having an HLB below 10, preferably below 8 and at leastone high HLB surfactant having an HLB above 10, preferably above 12.

The surfactant component is present in the delivery compositions in anamount of from about 3 to about 98, preferably from about 10 to about80, more preferably from about 15 to about 75, weight percent.

Surfactants which may be employed in the delivery compositions includeboth ionic agents, i.e., cationic, anionic or zwitterionic, andnon-ionic agents, or mixtures thereof. Examples of cationic surfactantsinclude cetyldimethylethylammonium bromide, cetylpyridinium chloride andother salts of these surfactants. Short chain monohydroxyl alcohols,such as C₁ to C₆ alcohols, are preferably not employed as surfactants inthese systems due to toxicity factors, thus the compositions aresubstantially free of such short chain monohydroxyl alcohols. Varioussurfactants also have permeation enhancement properties.

Examples of anionic surfactants include C₈₋₃₂ fatty acids and saltsthereof, preferably C₈₋₁₂, more preferably C₈ ; cholic acid andderivatives thereof such as deoxycholate, and its salts, ursodeoxycholicacid, and taurocholic acid; C₈₋₅₆ diesters of tartaric acid;phospholipids such as phosphatidic acid and phosphatidyl serine; C₅₋₂₉monoesters of lactic acid; C₈₋₂₀ sulfonates, including alkyl-, olefin-,and alkylaryl derivatives; tridecyl- and dodecylbenzene sulfonic acids;and C₅₋₃₃ sarcosine and betaine derivatives.

Zwitterionics include such phospholipids as lecithin,phosphatidylethanolamine, and sphingomyelins. The phospholipids areparticularly preferred for use as both the low and high HLB surfactants.

Among the non-ionic surfactants which may be employed are ethoxylatedcastor oil; C₅₋₂₉ mono-glycerides and ethoxylated derivatives thereof;C₁₅₋₆₀ diglycerides and polyoxyethylene derivatives thereof having 1 to90 POE groups; C₁₀₋₄₀ esters (10-40 carbon atoms in the alcohol) of longchain fatty acids (fatty acids having 16 carbon atoms and above); C₁₀₋₄₀alcohols; sterols such as cholesterol, ergosterol, and C₂₋₂₄ estersthereof; C₈₋₉₆ ethoxylated fatty esters; C₁₄₋₁₃₀ sucrose fatty esters;and C₂₀₋₁₃₀ sorbitol and sorbitan monoesters, diesters, and triesters,and polyoxyethylene (POE) derivatives thereof having 1 to 90 POE groups,e.g., polyoxyethylene sorbitan monooleate, sorbitol hexaoleate POE (50).

Preferred low HLB surfactants include C₉ to C₁₃ monoglycerides, C₁₉ toC₂₅ diglycerides of mono and poly unsaturated fatty acids, C₁₅ to C₂₃diglycerides, and C₃₅ to C₄₇ diglycerides of mono and poly unsaturatedfatty acids. Especially preferred low HLB surfactants are thosecontaining at least about 80 percent by weight, preferably at leastabout 90 percent by weight, and more preferably at least about 95percent by weight, of a monoglyceride or diglyceride containing C₆, C₇,C₈, C₉, or C₁₀ fatty acid functionalities, or mixtures thereof,preferably a C₉, C₁₁, or C₁₃ monoglyceride or mixtures thereof, and morepreferably a C₁₁ or C₁₃ monoglyceride or mixtures thereof. Commercialexamples of these surfactants include Imwitor 308, manufactured by HulsAmerica, Inc., having about 80-90% wt. C₁₁ monoglycerides; and GlycerolMonocaprylin, manufactured by Sigma Chemicals as1-monooctanoyl-rac-glycerol having about 99% wt. C₁₁ monoglycerides, andGlycerol Monocaprate, manufactured as 1-monodecanoyl-rac-glycerol bySigma Chemicals, having about 99% wt. C₁₃ monoglycerides. In certainpreferred embodiments, the low HLB surfactant, or mixture of low HLBsurfactants, will be only the above recited monoglycerides having apurity of at least about 80 weight percent.

Preferred high HLB surfactants include the sorbitan surfactants,preferably those having an HLB of from about 13 to about 17. Suchsurfactants include POE (20) sorbitan monooleate, monostearate,monopalmitate, and monolaurate sold commercially as the Tween 80, 60,40, and 20, respectively by ICI Inc., and POE (4) sorbitan monolauratesold commercially as Tween 21 by ICI. Also preferred are ethoxylatedcastor oil surfactants, preferably those having an HLB of from about 12to about 20, such as Cremophor EL, RH-40, and RH-60 and the PluronicF-series sold by BASF Inc. Potassium oleate is also preferred as a highHLB surfactant.

The low HLB surfactant is preferably present in the delivery compositionin an amount of from about 1 to about 40, preferably from about 5 toabout 30, more preferably from about 10 to about 30 weight percent, andin certain preferred embodiments from 20 to 30 weight percent. The highHLB surfactant is present in the delivery composition in an amount offrom about 2 to about 60, preferably from about 5 to about 50, and morepreferably from about 10 to about 40 weight percent.

The active agent is solubilized in water within the drug deliverycompositions. The water, or saline solution, is present in the deliverycomposition in an amount of from about 0.5 to about 15, preferably fromabout 1 to about 10, more preferably from about 2 to about 8, weightpercent, however in some high water systems, the water is present in anamount of from greater than 5 to about 15, preferably from 8 to about15, weight percent. This low level of water allows for solubilization ofthe active agent and also provides compatibility between the deliverycomposition and the capsule composition.

Polyethylene glycol (PEG) is incorporated into the delivery compositionsto promote compatibilty with the capsule composition. The capsulesuseful with the present invention include hard and soft gelatin capsulesand starch capsules. The hard and soft gelatin capsules are made fromgelatin blends as fully discussed in The Theory and Practice ofIndustrial Pharmacy, Lachman et al., Lea & Febiger, p. 374-408 (3d Ed.1986), which is hereby incorporated by reference in its entirety. Thegelatin is a heterogeneous product derived by irreversible hydrolyricextraction of treated animal collagen from such sources as animal bones,hide portions, and frozen pork skin. The gelatin can be blended withplasticizers, such as glycerin USP and sorbitol USP, and water. Theratio of glycerin to gelatin is from about 0.4:1 to about 0.8:1 for thehard and soft gelatin capsules, respectively. The moisuture content forhard gelatin capsules ranges from about 10-16% and from about 5-12% forsoft gelatin capsules at a relative humidity of about 25% at about 22°C. The gelatin capsules can also contain such additives aspreservatives, colorants, flavorants, etc. Commercially availablegelatin capsules are these made by CAPSUGEL, a division ofWarner-Lambert Co., which are available in a general capsule size rangeof from #5 to #000 having volumes of from about 0.1-1.4 ml.

The PEG component is present in the delivery compositions in an amountof from about 2 to about 60, preferably from about 5 to about 55, andmore preferably from about 15 to about 55, weight percent. The PEGcomponent typically has a weight average molecular weight of from about200 to about 1200 and commercially available PEG materials include PEG200, PEG 300, PEG 400, PEG 540, PEG 600, PEG 800, and PEG 1000 allcommercially available from, for example, Union Carbide Corp. in bothfood or pharmaceutical grades. The PEG component also functions as asolvent for the low HLB surfactants and permeation enhancers, and as astabilizer for the active agent, especially proteins and peptides.

A plasticizer can also be incorporated into the delivery compositions toprevent mass transfer between the capsule and the delivery compositions.Such plasticizers include sorbitol, mannitol, glycerin, propyleneglycol, and sugar compounds such as sucrose, glucose, fructose, lactoseand similar sugar compounds. The plasticizer is present in an amount offrom about 0.5 to about 10, preferably from about 0.5 to about 8, andmore preferably from about 1 to about 5, weight percent of the deliverycomposition. Propylene glycol is preferably not employed as aptasticizer in the compositions of the present invention for their useas encapsulated products since it is believed that propylene glycolcauses capsule instability during storage. Thus, the compositions forencapsulated use can be prepared provided that the plasticizer is notpropylene glycol in certain preferred embodiments.

In one embodiment of the present invention, the delivery compositionscan be described as having an aqueous phase, that is, components thatare highly soluble with the water and not considered to be high HLBsurfactants. The aqueous phase contains primarily the water, PEGcomponent, and plasticizer component. This aqueous phase is present inthe delivery composition in an amount of from about 1 to about 70,preferably from about 5 to about 60, and more preferably from about 8 toabout 55, weight percent. The aqueous phase contains a major amount ofthe PEG component and a minor amount of water or saline, andplasticizer. The aqeuous phase contains from about 60 to about 95,preferably from about 70 to about 90, and more preferably from about 75to about 90 weight percent of the PEG component. The water, or saline,content of the aqueous phase is from about 2 to about 30, preferablyfrom about 5 to about 15, more preferably from about 7 to about 13,weight percent. The ratio of the PEG component to the water in thecompositions is generally at least about 2:1, preferably from about 2:1to about 99:1, more preferably from about 4:1 to about 95:5, and evenmore preferably from about 5:1 to about 95:5. The plasticizer is presentin an amount of from about 1 to about 15, preferably from about 2 toabout 12, and more preferably from about 3 to about 9, weight percent ofthe aqueous phase.

The active agent to be incorporated into the drug delivery compositionsis preferably water-soluble. The water-soluble active agent can be anybiologically active, preferably therapeutic material, particularlywater-soluble proteins, peptides and other pharmaceutically-activecompounds, i.e., drugs or medicaments, and compounds which may have useas diagnostic agents. Vitamins and other food supplements which are notcommonly defined as being "therapeutic" are not within the definition ofthe active agent.

Therapeutic agents suitable for use in these systems are characterizedby the following general properties. The agents are polar, water solublecompounds with an octanol:water partition coefficient less than about0.1, preferably less than 0.05 and more preferably less than about 0.001when the aqueous phase has a pH of from about 5.5 to about 8.5, the pHrange of the mammalian intestinal tract. The agents have molecularweights greater than about 200, preferably greater than 300 and morepreferably greater than 400. Suitable agents are also characterized bypoor absorption through the GI tract with oral bioavailablilities(compared to i.p. availabilities) less than about 50%, preferably lessthan about 35% and more preferably less than about 20% when administeredat therapeutic dosage levels.

By "therapeutic" is meant an amount of the agent that produces the usualand desired pharmacological or physiological response to that agentelicited when it is administered by parenteral routes. The amount ofactive material to be administered to be "therapeutic" will be easilydetermined by those skilled in the art based upon concentration ofdosage and the repetition of the dosage.

Chemical classes of suitable therapeutic agents include the watersoluble proteins or peptides. One group of agents are water solublepeptides having a molecular weight from about 300 to about 2,000 (allmolecular weights herein are weight average) and containing at least oneand preferably two or more peptide bonds. A second group of agents arewater soluble polypeptides from about 2,000 to about 10,000 weightaverage molecular weight having at least three and preferably five ormore peptide bonds. A third group of agents are water soluble proteinshaving molecular weights greater than 10,000 and containing at least sixand preferably ten or more peptide bonds.

These active agents are admixed with the delivery compositions to formthe drug delivery compositions. The general amount of active agent is upto about 500 mg per gram of the drug delivery composition and in mostcases from about 0.5-300 mg/g drug delivery composition. The amount ofactive agent included in the drug delivery composition may be variedconsiderably, depending upon its solubility and activity, the use forwhich it is intended, the amount of emulsion to be employed, and thelike.

Suitable therapeutic peptides of molecular weight 300 to 2,000 having 3to 10 amino acid moieties include: fibrinogen receptor antagonistpeptides, RGD containing peptides, which are tetrapeptides of averagemolecular weight of about 600, having the amino acidsarginine-glycine-aspartic acid, in that order, as part of their sequencewith the fourth position of the tetrapeptide variable. Such peptides arehighly potent platelet aggregation inhibitors active at plasmaconcentrations as low as 1 pmol/mL. A preferred fibrinogen antagonist isthe peptide cyclo(S,S)-N.sup.α -acetyl-Cys-(N.sup.α-methyl)Arg-Gly-Asp-Pen-NH₂ (SEQ ID NO:1) prepared by the method of Aliet al., published application EP 0 341 915 whose disclosure is hereinincorporated by reference in its entirety. Also preferred is the peptidecyclo(S,S)-(2-mercapto)benzoyl-(N.sup.α-methyl)Arg-Gly-Asp-(2-mercapto)phenylamide which may be prepared by themethod disclosed in published EPO 0423212, Application No. 90311537.6whose disclosure is herein incorporated by reference in its entirety.

RGD-containing peptides and peptide-like molecules are generally presentin amounts ranging from about 10 mg to about 500 mg per gram of the drugdelivery composition depending on the solubility and therapeutic potencyof the compound.

Other fibrinogen antagonists useful in the present invention are thosepeptides disclosed in Pierschbacher et al., WO 89/05150 (US/88/04403);Marguerie, EP 0 275 748; Adams et al., U.S. Pat. No. 4,857,508;Zimmerman et al., U.S. Pat. No. 4,683,291; Nutt et al., EP 0 410 537;Nutt et al., EP 0 410 539; Nutt et al, EP 0 410 540; Nutt et al., EP 0410 541; Nutt et al., EP 0 410 767; Nutt et al., EP 0 410 833; Nutt etal., EP 0 422 937; Nutt et al., EP 0 422 938; Alig et al., EP 0 372 486Ohba et al., WO 90/02751 (PCT/JP89/00926); Klein et al., U.S. Pat. No.4,952,562; Scarborough et al., WO 90/15620 (PCT/US90/03417); Ali et al.,PCT US 90/06514, filed Nov. 2, 1990; peptide like compounds as disclosedin Alig et al., EP 0 381 033; and Alig et al., EP 0 384 362, thedisclosures of all of these being incorporated herein in theirentireties by reference; and the cyclic RGD peptides: ##STR1##

Enkephalins and analogues are other examples of peptides that may beusefully incorporated into these formulations. These peptides haveanalgesic properties and are based on the structures of the twonaturally occurring enkephalins, Leu⁵ !-enkephalin, a pentapeptide withthe sequence, H₂ N-Tyr-Gly-Gly-Phe-Leu-OH (SEQ ID NO. 3, MW=556), andMet⁵ !-enkephalin, with a sequence, H₂ N-Tyr-Gly-Gly-Phe-Met-OH (SEQ IDNO.4, MW=574). Examples of analogues include peptides in which one ortwo of the natural L-stereoisomers of the amino acid residues isreplaced by the corresponding D-stereoisomer, such as D-Ala², Leu⁵!-enkephalin (MW=570) or D-Ala², D-Met⁵ !-enkephalin (MW=588). Alsouseful are analogues containing one or more non-amino acid or chemicallymodifier amino acid moieties, such as D-Pen²,5, PCl-Phe⁴ !-enkephalin(MW=680) which interacts selectively with the delta-class of opioidreceptor (see Vaughn, L. K., et.al, Life Sciences, 45, 1001, 1989,incorporated herein in its entirety by reference).

Another useful class of peptides are hexapeptides related to growthhormone releasing peptide (GHRP). Specific examples include the peptideHis-D-Trp-Ala-Trp-D-Phe-Lys-NH₂ and related homologues and analogues.Also useful is the analogue Ala-His-D-βNal-Ala-Trp-D-Phe-Lys-NH₂, whereD-Trp is replaced by D- β-naphthyl!-alanine (C. Y. Bowers, J. Pediatr.Endocrinol., 6, 21, 1993, incorporated herein in its entirety byreference). Growth hormone releasing peptides are disclosed, forinstance, in Momany, U.S. Pat. No. 4,411,890; Momany, U.S. Pat. No.4,410,513; Momany, U.S. Pat. No. 4,410,512; Momany, U.S. Pat. No.4,228,158; Momany, U.S. Pat. No. 4,228,157; Momany U.S. Pat. No.4,228,156; Momany, U.S. Pat. No. 4,228,155; Momany, U.S. Pat. No.4,226,857; Momany U.S. Pat. No. 4,224,316, Momany U.S. Pat. No.4,223,021; Momany, U.S. Pat. No. 4,223,020; Momany, U.S. Pat. No.4,223,019; Bowers et al., U.S. Pat. No. 4,880,778; Bowers et al., U.S.Pat. No. 4,880,777; Bowers et al., U.S. Pat. No. 4,839,344; Bowers etal., U.S. Pat. No. WO 89/10933 (PCT/US89/01829); Bowers et al., EP-A 398961, Bowers et al. EP-A 400 051, all of which are fully incorporatedherein by reference. These compounds are useful for accelerating thegrowth of humans and animals.

Antagonists of GHRP are useful in clinical situations where abnormallyaccelerated growth or excessive plasma levels of growth hormone areencountered. Examples of a specific GHRP antagonist include thehexapeptide His-D-Trp-D-Lys-Trp-D-Phe-Lys-NH₂. Both agonists andantagonists of GHRP are usefully present in the range of 0.001 to 100 mgper gram of drug composition, depending on their potency.

Nonapeptidyl vasopressin V₁ and V₂ receptor agonists and antagonists areused clinically to treat conditions of excessive urinary output andblood clotting factor VIII deficiency. Particularly useful agentsinclude arginine vasopressin (AVP), lysine vasopressin (LVP) anddesmopressin(dDAVP), molecular weights 1084, 1056 and 1069 respectively.Desmopressin is particularly preferred for incorporation into an oraldosage form, because it has a longer plasma half-life and lacks thepressor (vasoconstricting) activities of AVP or LVP. Desmopressin hasbeen utilized in an oral dosage form, but the oral bioavailability ispoor, only 0.1 to 0.2% (A. Fjellestad-Paulsen, O. Paulsen, L.d'Agay-Abensour, S. Lundin and P. Czernichow, Regulatory Peptides 43,303-307, 1993, incorporated herein in its entirety by reference). AVP,LVP or dDAVP are usefully incorporated into the formulation at levelsranging from about 0.01 to 10.0 mg per gram of drug composition. OtherV₁ or V₂ vasoproessin receptor agonists or antagonists which arehomologues or analogues of the above compounds may be incorporated athigher levels, but generally less than 200 mg per gram of drugcomposition, depending on their therapeutic potency and solubility.

Yet another class of useful peptides include luteinizinghormone-releasing hormone (LH-RH) and its analogues. These peptidescontain about 10 natural or synthetical produced amino acid residues andhave molecular weights ranging from about 1,000 to about 1600. Suitableexamples include LH-RH itself, with a sequence ofpGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH₂ (SEQ ID NO.5, MW=1182)where pGlu stands for a pyroglutamic acid residue and the C-terminus ofthe peptide is amidated (--NH₂); the LH-RH agonist analogue, Des-Gly¹⁰,D-Trp⁶, Pro⁹ !-LH-RH, ethyl amide (MW=1283); and the LH-RH antagonist,Antide (MW=1592) which has a sequenceN-acetyl-D-βNal-p-Cl-D-Phe-3-Pyridyl-D-Ala-Ser-N-ε-Nicotinoyl-Lys-N-ε-Nicotinoyl-D-Lys-Leu-N-ε-Isopropyl-Lys-Pro-D-Ala-NH₂.Leuprolide, 5-OxoPro-His-Trp-Ser-Tyr-D-Leu-Leu-Arg-pro-NHC₂ H₅(MW=1210), is another LH-RH analogue and is useful for the treatment ofprostatic carcinoma.

Melanocyte stimulating hormones (MSH's) and analogues, having molecularweights ranging from about 800 to about 3000, may also be usefullyincorporated into these formulations. Particularly preferred areanalogues displaying prolonged circulatory half-lives and/or increasedresistance to proteolytic degradation.

Peptidyl proteinase inhibitors are another category of peptides andpeptide analogues that may be usefully incorporated into the drugcomposition. Particularly preferred are: inhibitors ofmetalloproteinases, such as collagenase and elastase, which are usefulin treating certain metastatic cancers and certain inflammatorydiseases, such as arthritis; inhibitors of proteases coded on viralgenomes, such as the HIV-1 and HIV-2 viral proteases; inhibitors ofangiotensin converting enzyme (ACE inhibitors) or of renin, useful inthe treatment of hypertension; and inhibitors of blood clotting cascadesproteases, such as thrombin inhibitors, useful for treating thrombosis.Also useful as antithromobics are peptides and polypeptide fragments ofthe leech protein hirudin, as well as analogues of these fragments andhirudin itself.

Calcitonins, such as those set forth in U.S. Pat. No. 5,002,771 which isincorporated herein in its entirety, are a set of therapeuticpolypeptides useful for treating hypercalcemia and bone loss. Preferredcalcitonins for incorporation into the formulation are salmon, eel andhaman calcitonins. Salmon calcitonin and eel calcitonin are mostpreferred because of their higher potency and more favorablepharmacokinetic profile. Human calcitonin is preferred in those patientswhere adverse reactions or insensitivity to the others is known orsuspected. Synthetic salmon, eel or human calcitonins have the sameamino acid sequence as their naturally occurring counterparts, but may,in some cases, be truncated or chemically altered versions of thenatural molecule, as for example is the case for carbacalcitonin whichis Des-Cys¹, Asu⁷ !-eel calcitonin. Their molecular weights range fromabout 3300 to 3500.

Other polypeptide regulators of calcium metabolism which could beusefully included in the formulation include the 84 amino acid residuepolypeptides human or bovine parathyroid hormone (PTH) with molecularweights of 9425 and 9511, respectively, and truncated versions andbiologically active fragments thereof having 14 to 83 amino acidresidues and molecular weights from 1400 to 9950. Also useful in thiscategory are PTH-related peptides, such as the human hypercalcemia ofmalignancy peptide which a has 86 amino acid residues and a molecularweight of 9903. Biologically active fragments of this molecule having 14to 85 amino acid residues and molecular weights from about 1400 to about9950 may also be usefully included in the formulation, as well aspolypeptide analogues of such fragments having agonist or antagonistactivities.

Antrial natriuretic peptides (ANP's) and their analogues arepolypeptides useful for treatment of hypertension. Particularlypreferred for use in these formulations are human ANP's and theiranalogues with molecular weights of from about 1000 to about 4000. Brainnatriuretic peptides are also useful for this purpose.

The insulins are another group of polypeptides which may be incorporatedinto the formulation. Human, bovine, porcine or ovine insulins orchemically modified derivatives thereof would be particularly preferred.This insulins are disulfide-linked, dimeric polypeptides having twodistinct chains, A and B, and a molecular weight of about 6000 for thedimeric molecule.

Other useful polypeptides in this molecular weight range include amylin,insulin-like growth factors I, II and III (IGF-I, IGF-II, IGF-III) ,somatomedins, epidermal growth factor (EGF), and transforming growthfactor-α (TGF-α). Polypeptide analogues of these molecules may also beincorporated into the formulation.

Proteins useful for incorporation into these formulations include:human, bovine, ovine or porcine growth hormone; α-, β-, orγ-interferons; lymphokines, such as interleukins 1 to 6; growth factors,such as platelet-derived growth factor, acidic or basic fibroblastgrowth factor; therapeutic enzymes, such as asparaginase or superoxidedismutase; erthropoietins; and monoclonal antibodies or theirantigen-binding fragments.

Further, suitable agents include water soluble complex polysaccharideshaving at least two and preferably three or more monosaccharide unitsand additionally containing one or more of the following chemicalsubstituents: amino groups (free or acylated), carboxyl groups (free oracylated), phosphate groups (free or esterified) or sulfate groups (freeor esterified).

Particularly preferred polysaccharides include heparins, useful asanticoagulants, and polysaccharide inhibitors of the mammalian celllectins, known collectively as `selectins`, useful as anti-inflammatoryagents.

Also, suitable agents include nucleosides, nucleotides and theirpolymers. Suitable nucleosides include 3'-azido-3'-deoxythimidine,2',3'-dideoxy-derivatives of adenosine, cytidine, inosine, thymidine orguanosine. Suitable polynucleotides include "anti-sense" nucleotideshaving 3 to 30 nucleotide bases with nucleotide sequences complimentaryto those coding for viral proteins or RNA's, oncogene proteins or RNA's,or inflammatory proteins or RNA's. Also useful are polynucleotideshaving 3 to 30 bases capable of forming triple helix structures with theDNA coding for the above.

Preferred water soluble active agents include RGD fibrinogen receptorantagonists, enkephalins, growth hormone releasing peptides andanalogues, vasopressins, desmopressin, luteinizing hormone releasinghormones, melanocyte stimulating hormones and analogues, calcitonins,parathyroid hormone, PTM-related peptides, insulins, atrial natriureticpeptides and analogues, growth hormones, interferons, lymphokines,erthropoietins, interleukins, colony stimulating factors, tissueplasminogen activators, tumor necrosis factors, complex polysaccharides,and nucleosides, nucleotides and their polymers.

Drugs that can be employed in this system are water soluble drugs whichare characterized by having low oral bioavailability. Examples of someof the drugs that can be employed include: anticoagulants, such asheparin or its derivatives; antimicrobials, such as penicillin G,carbenicillin, meziocillin and other poorly absorbed penicillinderivatives; cephalosporins, such as cephalothin, cefoxitin, cefotaximeand other molecules in this series normally administered by injection;antineoplastic drugs, such as fluorouracil, cytarabine, azauridine,thioguanine, vinblastine, vincristine, and bleomycin;anti-inflammatories, such as aurothioglucose and gold sodium thiomalate;and antiparasitic drugs, such as suramin and mebendazole.

The drug delivery compositions can be formulated with agents forenhancing mucosal absorption of peptides and proteins. These includebile salts such as trihydroxy bile salts, i.e. cholate, taurocholate,and glycocholate, dihydroxy bile salts, i.e. deoxycholate,taurodeoxycholate, chenodeoxycholate, and ursodeoxycholate, triketo bilesalts such as dehydrocholate. Non-ionic surfactants such aspolyoxyethylene ethers with alkyl chain lengths from 12-18 carbon atomsand polyoxyethylene (POE) chain lengths from 2-60,p-t-octylphenoxypolyoxyethylenes with 2-60 POE groups,nonylphenoxypolyoxyethylenes with 2-60 POE groups, polyoxyethylenesorbitan esters with 8-24 alkyl chain lengths and 4-80 POE groups, and1-dodecylhexahydro-2H-azepin-2-one(azone, laurocapram) can be used.Anionic surfactants such as sodium dodecyl sulfate and dioctyl sodiumsulfosuccinate can be used. Lysolecithins containing saturated fattyacyl chains having 8-24 carbon atoms or unsaturated fatty acyl chainshaving 1 to 4 double bonds and 16-24 carbon atoms can be used.Acylcarnitines, acylcholines and acylamino acids can be used, such asacylcarnitines having 12-20 carbon acyl groups and where the acyl groupshave 1-4 double bonds, acylcholines such as acyl choline esters of fattyacids having 8-22 carbon atoms and 1-4 double bonds, and acylamino acidssuch as N-acyl amino acids and dipeptides having acyl groups with 8-24carbon atoms and 1-4 double bonds and the amino acids having α or βamino groups and a molecular weight less than 350. Additionally, monoand polyunsaturated fatty acids and their salts having 14-24 carbonatoms and 1-4 double bonds, and salicyclic acid and its sodium salt,sodium 5-methoxy-salicylate can be used.

Preferred permeation enhancers include C₈₋₁₈ fatty acids, acylcarnatine,cholic acids, and phospholipids, or combinations thereof. These functionparticularly well in combination with the preferred low HLB surfactant,such as the mono- and di-glycerides having from C₈₋₁₀ fatty acidfunctionalities. A particularly preferred combination of permeationenhancers is a mixture of C₁₁ monoglyceride (such as Imwitor 308), oleicacid, and phospholipids.

The stabilization of the active agent, especially proteins or peptides,is generally enhanced by altering the pH and the buffering capacity ofthe aqueous phase of the compositions. Such compounds as HCl and NaOHcan be used to adjust the pH and such compounds as acetic acid can beused as buffers. A pH of below about 5 is typically preferred with suchproteins as calcitonin, dDAVP, RGD peptides and their analogs. The PEGcomponent itself can stabilize other proteinaceous agents such as humangrowth hormone.

Other components can be used in conjunction with the drug deliverycompositions to inhibit or prevent the degradation of the proteinaceousactive agents. Such components include protease inhibitors, enzymeinhibitors, and stabilizers as shown in U.S. Pat. No. 5,206,219 which isincorporated herein by reference. A preferred stabilizer iscyclodextrin.

In addition, there may optionally be included into the formulations suchother adjuvants as antioxidants, coloring agents, oil soluble drugs andthe like. Each of these components and adjuvants must be suitable foruse in the subject and will usually be food grade and/orpharmaceutically-acceptable materials.

The compositions of the present invention are biologically compatible inthat they are non-toxic and contain biodegradable or non-absorbablematerials. By non-toxic it is meant non-toxic dependent upon the routeof administration to a subject, in that the toxicity of one route maynot be equivalent to that of another route.

Adjuvants, such as preservatives, coloring agents, flavors oroil-soluble drugs, e.g., steroids, if any, should be included only inthose amounts which will not adversely affect the novel properties ofthe composition, generally in amounts of up to 20% by volume, based onthe total volume of the drug delivery composition.

The delivery compositions of this invention may readily be prepared bysimply mixing together with mild agitation the selected components inthe desired ratios at room temperature or at slightly elevatedtemperatures. No high-energy mixing or application of heat is necessary,although limited use of each may be employed, if desired, to increasethe rate of formation of the compositions. Moreover, the ingredients donot have to be added in any particular order other than that it ispreferred for the active agent to be present in the aqueous phase as thecomposition is formed. Preferably, however, the surfactant should firstbe mixed with the oil phase, followed by the addition of the aqueousphase components in the proper ratio. It is preferred to dissolve theactive agent in the water first, and then add this to the other aqueousphase components.

The delivery composition of the present invention can be formulated witha high melting oil, that is, an oil with a melting point above roomtemperature (22°-23° C.), preferably above about 30° C., in order toformulate a composition which is a solid at room temperature. Also, highmelting surfactants such as a C₁₀₋₄₀ ester of a long chain fatty acidand alcohols having at least about 12 carbon atoms, wherein thesesurfactants have melting points above room temperature, preferably aboveabout 30° C. Preferably, the composition will melt at body temperatures,generally between about 35°-40° C. The amount of high melting oil andthe melting point of that oil can vary, but the final composition issolid at room temperatures. The solid composition can be used as asuppository transport vehicle or as an oral transport vehicle. Thecomposition can either be formulated directly with the high melting oil,or the composition can be formulated first, after which the high meltingoil is blended with the composition. Such high melting oils are wellknown in the art and include, for example, partially hydrogenatedcoconut oils, palm oils, cocobutter, hydrogenated peanut oil, andvarious hydrogenated vegetable oils, along with combinations thereof.Preferred oils include hydrogenated coconut and palm oils and mixturesthereof. The high molecular weight PEG components can also be used toformulate a solid composition.

The administration, especially oral adminstration, of the active agent,contained within the drug delivery composition, is preferably in theform of a capsule. The capsule is generally a starch or gelatinmaterial. Certain active agents may be susceptible to the low pHenvironment of the stomach and should therefore be delivered to thehigher pH environment of the intestinal system. Although such activeagents are beneficially delivered in suppository form, if oral deliveryis desired, the capsule can be supplied with an enteric coating. Suchcoatings are well known in the art as are the methods of entericallycoating a capsule. The method of producing an enterically coated capsuleis as follows. The drug delivery composition containing the active agentis prepared and this composition is then placed into a capsule. Thecapsule is then coated with an enteric coating solution. The entericcoating solution contains the polymeric enteric coating substance andsolvents. The polymeric enteric coating substance is generally apharmaceutically acceptable polymer that will dissolve upon contact withintestinal fluids, pH of about 5.5 to 7.0, but will not dissolve in thelower pH stomach fluids. Enteric polymer coatings are readily availablecommercially, such as the Eastman® C-A-P™ (cellulose acetate phthalate)and C-A-T (cellulose acetate trimellitate) enteric coating materialsavailable from Eastman Chemical Products, Inc. Various techniques areknown to apply the entire polymer coating such as spray coating orimmersion coating and several layers of the enteric substance may berequired.

The invention will now be illustrated by, but is not intended to belimited to, the following examples.

EXAMPLES Example 1

Preparation of the Delivery Compositions

Various compositions were prepared containing the high level of PEG inthe aqueous phase of the transparent, stable compositions, which wereall liquids at room temperature. The compositions were prepared bysimply admixing the various components in random order. No active agentwas formulated with these compositions, however the addition of theactive agent can be made without altering the character of the resultingcomposition.

The resulting compositions are represented graphically in the phasediagram shown in FIG. 1. Apex A represents 100 wt. % of the aqueousphase, apex B represents 100 wt. % of the oil phase, and apex Crepresents 100 wt. % of the surfactant and permeation enhancers. Theshaded area represents compositions that produce transparent liquids.

The aqueous phase constituted 8.6 parts PEG 600, 1 part water, and 0.4parts sorbitol. The oil phase constituted Captex 200 (propylene glycoldicaprylate/caprate having a fatty acid composition of caproic (4.1 wt.%), caprylic (68.29 wt. %), capric (27.4 wt. %), lauric and higher (0.2wt. %), manufactured by Karlshams Lipid Specialties U.S.A.). Thesurfactant phase constituted 6 parts Imwitor 308 and 4 parts Tween 80(polyoxyethylene sorbitan mono oleate, HLB=15, manufactured by SigmaChemical). All parts being on a weight basis.

Example 2

Preparation of the Delivery Compositions

The phase diagram as described in Example 1 was made except that the PEG600 was replaced with PEG 300. The phase diagram is shown in FIG. 2.

Example 3

Preparation of the Delivery Compositions

The phase diagram as described in Example 1 was made except that the PEG600 was replaced with PEG 400. The phase diagram is shown in FIG. 3.

Example 4

Preparation of the Delivery Compositions

The phase diagram as described in Example 3 was made except that thesurfactant phase constituted 4 parts Imwitor 308 and 6 parts Tween 80.The phase diagram is shown in FIG. 4.

Example 5

Preparation of the Delivery Compositions

The phase diagram as described in Example 3 was made except that theaqueous phase constituted 8 parts PEG 400, 1 part sorbitol, and 1 partwater. The phase diagram is shown in FIG. 5.

Example 6

dDAVP Dog Study

A drug delivery formulation able to solubilize the peptide dDAVP wasprepared with the following composition:

    ______________________________________                                        Example 6a        Composition (% w/w)                                         ______________________________________                                        Captex 200        12.0                                                        Imwitor 308       28.8                                                        Tween 80          19.2                                                        PEG-400           32.4                                                        1N HCl            0.74                                                        Sorbitol          1.60                                                        Water             1.45                                                        10 mg/ml dDAVP in 40 mM                                                                         3.81                                                        Acetate Buffer, pH 5.0                                                        ______________________________________                                         dDAVP = 171 μg/g drug composition                                     

Sorbitol was first dissolved in water and hydrochloric acid, thenPEG-400, Tween 80, premelted Imwitor 308, and Captex 200 were added, andmixed until homogeneous. Meanwhile, dDAVP was dissolved in 40 mM acetatebuffer, pH 5.0 solution. The drug solution was admixed with theSorbitol/water/1N HCl/PEG-400/Captex 200/Tween 80/Imwitor 308 to form atransparent drug delivery composition. The same procedure was used toprepare the examples 6b, 6c and 6d with the following compositions (%w/w). In 6d, a drug-free acetate buffer solution was used.

    ______________________________________                                        Examples         6b        6c     6d                                          ______________________________________                                        Captex 200       12.0      12.0   12.0                                        Imwitor 308      28.8      28.8   28.8                                        Tween 80         19.2      19.2   19.2                                        PEG-400          32.4      32.4   32.4                                        1N HCl           0.74      0.74   0.74                                        Sorbitol         1.60      1.60   1.60                                        Water            4.67      5.08   5.26                                        10 mg/ml dDAVP in 40 mM                                                                        0.59      0.18   0.0                                         Acetate Buffer, pH 5.0                                                        dDAVP (μg/g)  59        18     0.0                                         ______________________________________                                    

METHODOLOGY

DDAVP or desmopressin is a synthetic analogue of vasopressin, which hasbeen demonstrated to have a longer half life in the bloodstream than thenative vasopressin. Pharmacologically, it has an antidiuretic effect,and so has been useful in the treatment of biabetes insipidus and ofpediatric nocturnal enuresis. It also elevates circulating levels ofFactor VIII, and so has been used in treating certain forms hemophilia.

Male beagle dogs weighing 9-12 kg were used in all experiments. Prior toeach study, all animals were fasted overnight but were allowed access towater ad libitum. The following study was used to demonstrate theadvantage of the dDAVP-containing transparent liquid encapsulated incapsules of this invention:

1. Peroral administration: Enteric coated hard gelatin capsules, size0el (0.78 ml) from CAPSUGEL, fill materials: 0.73 g of the drug deliverycompositions containing:

(i) 0 μg drug/g composition or 0 μg drug/capsule (Table 6D Example 6d)

(ii) 18 μg drug/g composition or 13 μg drug/capsule (Table 6C, Example6c)

(iii) 59 μg drug/g composition or 43 μg drug/capsule (Table 6B, Example6b)

(iv) 171 μg drug/g composition or 125 μg drug/capsule (Table 6A, Example6a)

2. Peroral administration: Enteric coated hard gelatin capsules, size0el, fill materials: 171 μg dDAVP mixed with dextrose as filler (Table6E).

3. Subcutaneous administration: 4 μg dDAVP/ml composition, 0.4 μgdDAVP/kg animal (Table 6F).

Plasma Factor VIII levels following administration of dDAVP was used asa pharmacodynamic response to the drug. Maximum response to dDAVP wasdetermined by measuring plasma Factor VIII response levels followingsubcutaneous administration of dDAVP (Table 6F). Administration ofcapsules containing compositions 6a through 6c provided dose response,composition 6d was a placebo control, dDAVP in dextrose provided acontrol is inert filler.

For studies involving capsule administration, a single capsule was givento each animal in each study. Blood samples were taken immediately priorto dDAVP administration (t=0), and at various times thereafter. Plasmalevels of Factor VIII were determined using commercially available kits.Values are expressed as percent change in Factor VIII levels, relativeto values obtained at t=0, and are shown as mean values±standard errorsof the mean, in Table 6.1.

RESULTS

A dose-dependent increase in plasma Factor VIII levels was observed indogs following administration of capsules containing 13, 43 and 125micrograms (μg) dDAVP per transparent liquid capsule (Tables 6C, 6B and6A). A similar degree of increase in Factor VIII levels was observedfollowing administration of 43 μg/capsule and 125 μg/capsule (Tables 6Band 6A). In contrast to this, the response in Factor VIII levels afteradministration of dDAVP at 12 μg/capsule (Table 6C) was notsignificantly different from levels observed in placebo-treated animals(Table 6D).

The enhancement effect of the transparent liquid formulation can furtherbe seen in Tables 6A and 6E, comparing administered using capsulescontaining dDAVP in transparent liquid and using capsules containingdDAVP in an admixture in which dextrose was used as an inert filler. Inthe latter case, the dDAVP showed virtually no response over the sixhour test period (Table 6E). This was in marked contrast to the maximalresponse observed in animals that had been given capsules containing thedDAVP in the transparent liquid of this invention (table 6A).

The comparison of Tables 6F and 6A shows that dDAVP, given bysubcutaneous injection at a does of 0.4 μg/kg, produced similar increasein Factor VIII levels as that which dDAVP was given orally in capsulewith the formulation of this invention at a dose of 10 μg/kg (125 μg/kg(125 μg/g, Table 6A).

                                      TABLE 6.1                                   __________________________________________________________________________    Compositions                                                                  A         B     C     D     E     F                                           Time                                                                              %  SEM                                                                              %  SEM                                                                              %  SEM                                                                              %  SEM                                                                              %  SEM                                                                              %  SEM                                      __________________________________________________________________________    0   0  0  0  0  0  0  0  0  0  0  0  0                                        0   0  0  0  0  0  0  0  0  0  0  0  0                                        2   59 12 68 10 21 9  16 19 15 12 59 14                                       5   54 14 64 8  29 4  39 25 13 9  58 15                                       10  36 22 70 15 23 7  53 18 13 15 61 15                                       i5  37 26 75 13 26 6  31 15 22 7  63 14                                       30  81 24 77 15 25 9  47 16 12 11 69 12                                       45  86 26 74 16 32 9  57 15 17 11 46 17                                       60  75 25 57 24 27 8  42 12 12 11 81 17                                       90  103                                                                              27 69 12 15 7  13 24 10 12 69 12                                       120 74 20 63 11 14 7  28 15 0  17 91 21                                       150 81 9  35 18 6  9  21 19 0  2S 82 20                                       180 60 10 59 14 6  6  13 16 0  12 83 22                                       240 34 11 66 19 4  10 8  16 0  26                                             300 48 9  79 11 1  8  19 16 0  8                                              360 35 11 77 12 11 5  29 11 0  16                                             __________________________________________________________________________

Particle Size Measurement

The particle size of composition 6d was determined using photoncorrelation spectroscopy. This composition had a viscosity of 106centipoises, and a refractive index of 1.455 and appeared transparent tothe naked eye.

A Brookhaven Instrument BI-9000AT with a 500 milliwatt laser source wasused and provided a count rate of about 57 kilocounts/sec. The particlesize was measured three times and the results were particle sizes of1.2, 1.8, and 3 nanometers, with a polydispersity of 0.43, 0.1, and0.72, respectively.

Example 7

Calcitonin Formulations

A formulation able to solubilize the peptide drug calcitonin in highconcentration was prepared that was found to be compatible with gelatincapsules. This formulation maximized the concentration of the aqueousphase to solubilize more drug, but minimized the water concentration toconfer compatibility with water soluble gelatin capsules. This wasaccomplished by replacing water in the polar phase with polyethyleneglycol and sorbitol, yielding a formulation in which there would be nosignificant exchange of moisture or plasticizer between the formulationand the gelatin shell. The composition prepared is shown in Table 7.1:

                  TABLE 7.1                                                       ______________________________________                                        Component      Concentration (% w/w)                                          ______________________________________                                        Calcitonin     0.12                                                           Water          4.00                                                           Sorbitol       1.60                                                           PEG-400        34.14                                                          Glacial Acetic Acid                                                                          0.24                                                           1N HCl         0.018                                                          Imwitor 308    28.80                                                          Tween 80       19.20                                                          Captex 200     12.00                                                          ______________________________________                                    

Calcitonin was first dissolved in water. Sorbitol was then added anddissolved, then a premixed solution of the acetic and hydrochloric acidsand the PEG-400 was added, and mixed until homogeneous. Meanwhile, theImwitor 308 was melted and admixed with the Tween 80 and Captex 200 toform a homogeneous mixture. The surfactant and oil mixture was admixedwith the drug/water/sorbitol/PEG-400/acids mixture to form a transparentliquid formulation.

The calcitonin was found to be chemically stable in this formulation forat least two months.

Example 8

Capsule Compatibilty

The composition of Example 7 was prepared without the drug to test thestability of the composition in a gelatin capsule. The composition usedis shown in Table 8.1:

                  TABLE 8.1                                                       ______________________________________                                        Component      Concentrate: (% w/w)                                           ______________________________________                                        Water          4.0                                                            Sorbitol       1.6                                                            PEG-400        34.14                                                          Glacial Acetic Acid                                                                          0.24                                                           1N HCl         0.018                                                          Imwitor 308    28.80                                                          Tween 80       19.20                                                          Captex 200     12.00                                                          ______________________________________                                    

The sorbitol was first dissolved in the water, then a premixed solutionof the acetic and hydrochloric acids and the PEG-400 was added, andmixed until homogeneous. Meanwhile, the Imwitor 308 was melted andadmixed with the Tween 80 and Captex 200 to form a homogeneous mixture.The drug/water/sorbitol/PEG-400/acids mixture to form a transparentliquid formulation.

This formulation was found to be compatible with, and stable when storedin, hard gelatin capsules from CAPSUGEL for at least two months. Thecapsules neither became brittle nor soft, and the formulation neithergained nor lost significant amounts of water to the capsule shell asshown in the Table 8.2. The formulation itself remained clear andhomogeneous, as determined by visual observation.

                  TABLE 8.2                                                       ______________________________________                                        Time (weeks) 0     2           4    8                                          H.sub.2 O! (% w/w)                                                                        4.9   5.07        4.60 4.31                                      ______________________________________                                    

Example 9

Calcein Bioavailability In Rats

Compositions A-F incorporating calcein as a marker were prepared forintraduodenal bioavailability studies in rats. Calcein solution, water,and sorbitol or glycerin were mixed together until the sorbitol orglycerin was dissolved, then the polyethylene glycol was added, andmixed until homogeneous. Meanwhile, the oil(s) and surfactants weremixed together to form a homogeneous mixture. The surfactant and oilmixture was admixed with the aqueous phase to form a transparent liquidformulation. In some cases, a small amount of 1N sodium hydroxide wasadded to bring the pH to the basic range before the liquid becametransparent (compositions C, D and E).

Composition A

A transparent liquid containing 3 mM calcein as a marker was preparedwith the following composition: Captex 200 (12% w/w), Imwitor 308 (29.8%w/w), Tween 80 (19.2% w/w), Polyethylene glycol 400 (32.4%/w), Sorbitol(1.6%/w), sterile water (3% w/w) and 100 mM Calcein solution in 10 mMTris pH 7.4 (3% w/w).

Composition B

A transparent liquid containing 4.2 mM calcein was prepared with thefollowing composition: Captex 200 (13% w/w), Imwitor 308 (26% w/w),Cremophor RH40 (26% w/w), Polyethylene glycol 400 (28% w/w), Glycerin(2.8% w/w), and 100 mM Calcein solution in 10 mM Tris pH 7.4 (4.2% w/w).

Composition C

A transparent liquid containing 2.9 mM calcein as was prepared with thefollowing composition: Captex 200 (12% w/w), Imwitor 308 (28.8% w/w),Tween 80 (22.3% w/w), Glycocholic acid (1.9% w/w), Sodium Taurocholate(1.9% w/w), Polyethylene glycol 600 (31% w/w), Glycerin (3.1% w/w),sterile water (1.2% w/w), 1N Sodium hydroxide (0.7% w/w), and 100 mMCalcein solution in 10 mM Tris pH 7.4 (2.9% w/w).

Composition D

A transparent liquid containing 3.0 mM calcein as was prepared with thefollowing composition: Captex 200 (11.5% sw/w), Imwitor 308 (23.4% w/w),Tween 80 (21.8% w/w), Glycocholic acid (3.7% w/w), Sodium Taurocholate(3.7% w/w), Polyethylene glycol 600 (28.7% w/w), Glycerin (1.3% w/w),sterile water (1.5% w/w'), 1N Sodium hydroxide (1.4% w/w), and 100 mMCalcein solution in 10 mM Tris pH 7.4 (3% w/w).

Composition E

A transparent liquid containing 1.5 mM Calcein as a marker was preparedwith the following composition: Captex 200 (7% w/w), Cod liver OilMethyl ester (5% w/w), Imwitor 308 (28.6%/w), Tween 80 (19.1% w/w),Polyethylene glycol 400 (34% w/w), Sorbitol (1.6% w/w), sterile water(2.9% w/w), 1N NaOH (0.2% w/w), and 100 mM Calcein solution in 10 mMTris pH 7.4 (1.5% w/w).

Composition F

A transparent liquid containing 2.9 mM calcein as was prepared with thefollowing composition: Captex 200 (10% w/w), Imwitor 308 (25% w/w),Glycocholic acid (5% w/w), Sodium Taurocholate (5% w/w), Linoleic acid(20% w/w), Polyethylene glycol 600 (29% w/w), Sorbitol (1.5% w/w), and100 mM Calcein solution in 10 mM Tris pH 7.4 (4.5% w/w)

Methodology

Formulations in examples A-F were dosed intraduodenally to assess thebioavailability of calcein (5(6)-carboxyfluorescein, MW 623) using anunconscious rat model (Walker et al., Life Sciences, 47, 29-36, 1990),and compared with that obtained when calcein was dosed as a buffersolution. The concentrations of the calcein in plasma was measured usingfluorescence spectroscopy. The dosing level was 2.5 μmol calcein/kganimal. The results for Compositions A-F are given in the followingTable 9.1:

                  TABLE 9.1                                                       ______________________________________                                                 Calcein Bioavailability                                              EXAMPLE    # Rats       Result  SEM                                           ______________________________________                                        A          10           27.6    4.8                                           B          5            25.8    7.1                                           C          12           39.7    6.8                                           D          4            35.4    1.5                                           E          4            33.4    13.1                                          F          5            39.5    5.6                                           Buffer     5            1.3     0.5                                           ______________________________________                                    

Example 10

Calcitonin bioavailability in rats

Compositions A-C incorporating calcitonin were prepared forintraduodenal bioavailability studies in rats. The bioavailability ofcalcitonin (used in the treatment of hypercalcemia by lowering Ca⁺²serum levels) was determined using an unconscious rat model.

Composition A

A transparent liquid containing about 30 μg/ml calcitonin was preparedwith the following composition: Captex 200 (11.4% w/w), Imwitor 308(23.3% w/w), Tween 80 (21.7% w/w), Glycocholic acid (3.7% w/w),chenodeoxycholic acid (3.7% w/w), PEG 600 (28.6% w/w), Glycerin (1.3%w/w), acetic acid (0.53% w/w), 1N NaOH (1.4% w/w), 750 mcg/ml calcitoninsolution (3.9% w/w) and water (4.4% w/w). Two other similar formulationswith about 10 μg/ml and 3 μg/ml calcitonin were prepared by replacingpart of the calcitonin solution with water.

Composition B

A transparent liquid containing about 30 μg/ml calcitinin was preparedwith the following composition: Captex 200 (11.7% w/w), Imwitor 308 (28%w/w), Tween 80 (18.7% w/w), Molecusol (β-cyclodextrin) (3% w/w) PEG 400(31.3% w/w), sorbitol (1.7% w/w), 1 n HCl (0.33% w/w), 750 mcg/mlcalcitonin solution (3.9% w/w), and water (1.43% w/w). Two other similarformulations with about 10 μg/ml and about 3 μg/ml calcitonin wereprepared by replacing part of the calcitonin solution with water.

Composition C

A transparent liquid containing about 30 μg/ml calcitonin was preparedwith the following composition: Captex 200 (11.7% w/w), Imwitor 308 (28%w/w), Polyoxyethylene 9 Lauryl Ether (18.7% w/w), PEG 1000 (31% w/w),sorbitol (1.7% w/w), 750 mcg/ml calcitonin solution (3.9% w/w), andwater (5.1% w/w). Two other similar formulations with about 10 μg/ml andabout 3 μg/ml calcitonin were prepared by replacing part of thecalcitonin solution with water.

Methodology

Fasted rats (male Sprague-Dawley; 87-106 g) were anaesthetized with i.p.pentobarbital. An incision in the neck was made to reveal the jugularvein. A catheter was inserted into the jugular vein to collect bloodsamples for calcium analysis. An incision was made into the peritonealcavity and the duodenum was exposed. A purse-string suture wasintroduced into the surface of the duodenum.

The animals were dosed intraduodenally at 1 ml per kg body weight andintravenously with 2 ml per kg body weight and then flushed with 100 μlof saline. Therefore, the intraduodenal administration was about 3 μg,10 μg, and 30 μg per kg animal body weight and the intraveneousinjection (5 i.u. calcitonin=1 μg at 3 i.u./ml) was about 1.2 μg/kg bodyweight.

After the formulation was introduced, the purse-string suture wastightened as the syringe needle was withdrawn to prevent leakage of theformulation into the peritoneal cavity.

The peritoneum was closed with surgical staples and the animals werekept anaesthetized through the duration of the experiment. Blood samples(50 to 200 μl) were taken periodically during the course of theexperiment. The blood samples were used to prepare serum which was usedto determine serum Ca⁺² (free ionized calcium) levels using Beckman 700calcium clinical assay kits. The serum calcium levels are reported inTable 10.1 are in units of mg/dL. The number of rats for each group isgiven as the (#) value.

                  TABLE 10.1                                                      ______________________________________                                        Calcium Assay Results                                                         Admini-                                                                       stration/       A          B        C                                         Concen-  Time           SEM        SEM        SEM                             tration  (hr.)  Mean    (#)  Mean  (#)  Mean  (#)                             ______________________________________                                        IV       0      6.7     0.3  6.7   0.3  6.5   0.3                                                     (3)        (3)        (4)                                      1      5.3     0.3  6.0   0.6  5.2   0.2                                                     (3)        (3.)       (4)                                      3      3.7     0.7  5.3   0.3  5.2   0.2                                                     (3)        (3)        (4)                             ID       0      6.5     0.3  6.7   0.2  7.0   0.8                             3 mg/ml                 (6)        (17)       (5)                                      1      5.8     0.2  6.1   0.1  6.4   0.7                                                     (6)        (7)        (.5)                                     3      6.3     0.5  6.3   0.2  6.4   0.7                                                     (6)        (7)        (5)                             ID       0      6.7     0.3  6.7   0.2  7.0   1.3                             10 mg/ml                (6)        (8)        (5)                                      1      5.3     0.7  5.5   0.3  4.8   1.2                                                     (6)        (8)        (5)                                      3      5.2     1.2  5.9   0.3  5.6   1.6                                                     (6)        (8)        (5)                             ID       0      7.0     0    7.6   0.4  7.3   1.1                             30 mg/ml                (6)        (7)        (7)                                      1      5.8     0.2  5.7   0.3  5.1   0.8                                                     (6)        (7)        (7)                                      3      5.5     0.3  5.7   0.5  4.9   0.6                                                     (6)        (7)        (7)                             ______________________________________                                    

Example 11

Experiments can be carried out using rats with the 20 formulations ofthis invention to evaluate them as a vehicle for the delivery of RGDpeptides, such as the peptide cyclo(S,S)-N.sup.α -acetyl-Cys-(N.sup.α-methyl) Arg-Gly-Asp-Pen-NH₂.

Formulations

The test formulations are prepared according to the methods of theapplication, such as those set forth in FIGS. 1-5.

Test Method

Intravenous (i.v.) Administration:

Fasted rats are anesthetized with an intraperitoneal (i.p.) injectionand surgically fitted with a jugular catheter (ACUC protocol #90-151).Rats are allowed to recover from the surgery for 1 day. Catherized ratsare fasted for 18 hr prior to the experiment. Each rat receives either a1 mg or 3 mg peptide/kg animal dose by lateral tail-vein administration.Blood samples of 0.5 ml aliquots are collected at 0, 1, 3, 5, 10, 15,30, 45, 60, 90, 120, 150, and 180 min. The 0 min sample is taken 15 minprior to administration of the dose. Plasma is removed from the wholeblood by centrifugation at 1600×g for 5 min, and then plasma is storedat -20° C. in 250 μl aliquots per sample. The blood pellet isreconstituted with 12.5 units heparinized saline and returned to theappropriate rat via the jugular catheter. After the experiment, rats areeuthanized with i.v. administration of pentobarbital.

Intraduodenal (i.d.) Adminstration:

Fasted rats are administered an i.p. injection of anesthesia cocktailand surgically fitted with jugular and duodenal catheters. Rats areallowed to recover from the surgery for 4-5 days (ACUC protocol#91-055). Catherized rats are fasted 18-20 hr prior to the experiment.Each group of rats receives either 10 mg peptide/kg animal in eachformulation (3.3 ml/kg) or 6.5 mg peptide/kg animal in each formulation(3.3 ml/kg). A saline control is administered to a group of ratscontaining 10 mg peptide/kg animal in a saline solution. Blood samplesof 0.5 ml aliquots are collected via jugular catheter in heparinizedeppendorf tubes at 0, 10, 30, 60, 120, 180, 240, and 1440 min. The 0 minsample is taken 15 min prior to administration of the dose by duodenalcalheter. Plasma is collected for analysis and the blood returned torats as described in the i.v. administration protocol. After 24 hr, ratsare euthanized by i.v. administration of pentobarbital, exsanguinated,and a macroscopic observation of the intestinal tract is performed.

Post-Column HPLC Fluorescence Assay:

For samples and standards, plasma components are precipitated with 0.6ml cetonitrile, and then pelleted by centrifugation at 16,000×g for 20min. The supernatant is removed, and then dried to powder under N₂ at40° C. Powder is dissolved in 0.5 ml 1% TFA solution, and then processedby solid-phase extraction procedure (SPEP). SPEP is as follows: 1)condition 1 ml C₁₈ columns with methanol, and then rinse columns with 1ml water, 2) standards and samples are applied to columns, and thenrinsed twice with 1 ml water, 3) standards and samples are collected intubes upon elution from column with methanol by two 0.5 ml aliquots. Thesamples and standards are dried to powder under N₂ at 40° C., and thendissolved in 100 μl of 10% methanol: 90% ultrapure water solution.Standards and samples are placed in HPLC vials. Vials with standards areplaced before and after vials containing the samples for HPLC analysis.For the peptide standards, an aliquot is injected for analysis based onthe concentration of the standard as follows: 50 μl aliquot is injectedfor analysis by post-column fluorescence detection. Fluorescencechromatography data are collected and integrated using NelsonChromatography Data System. The peak area ratio (Y) and peptide standardconcentration (X) are used to determine the slope of a line which isforced through the origin from the equation: slope=(sum of X*Y)/(sum ofX²). The slope represents the relationship between peak area ratio andpeptide plasma concentration for the samples.

Results

The area under the plasma concentration curve (AUC) is determined foreach test group. The percentage bioavailability is determined by theequation with the average AUC from iv administration: (AUC_(id)/AUC_(iv))*(mg/kg_(iv) /mg/kg_(id))!*100.

Example 12

Studies can he conducted to determine whether the formulations of thepresent invention can enhance the bioavailability of the proteinaceousmaterial disclosed in U.S. Pat. No. 4,703,036(N-methyl-D-phenylalanyl-L-propyl-L-argininal sulfate), which isincorporated herein in its entirety, which is a tripeptide-aldehydederivative having a molecular weight of about 515 (CAS No. 126721-07-1),the peptide having anticoagulant activity.

The formulation can he prepared according to the compositions set forthin FIGS. 1-5 with about 0.7% wt. peptide. A control compositioncontaining the peptide in saline is also prepared. Both preparationscontain 5 mg peptide/ml composition.

Male Fisher 344 rats are anesthetized with methoxyflurane, and a midlineabdominal incision is made to expose the intestine and 5 mg peptide/kganimal in the form of the microemulsion is injected into the duodenallumen distally. The injection site and surgical incision site are closedwith surgical adhesive and the animals are allowed to recover. Bloodsamples are collected in heparinized Vacutainer tubes via cardiacpuncture at appropriate times. Blood is reduced to plasma and plasmasamples are analyzed for the peptide by HPLC with UV detection.

The results are determined by calculating the area under the curve (AUC)for the inventive formulations compared to the saline.

    __________________________________________________________________________    SEQUENCE LISTING                                                              (1) GENERAL INFORMATION:                                                      (iii) NUMBER OF SEQUENCES: 5                                                  (2) INFORMATION FOR SEQ ID NO:1:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 5 amino acid residues                                             (B) TYPE: Amino Acid                                                          (C) STRANDEDNESS:                                                             (D) TOPOLOGY: Unknown                                                         (ii) MOLECULE TYPE: Peptide                                                   (ix) FEATURE:                                                                 (A) NAME/KEY: Modified-site                                                   (B) LOCATION: 1                                                               (D) OTHER INFORMATION: cyclo (S,S)- N`-acetyl-Cys                             (ix) FEATURE:                                                                 (A) NAME/KEY: Modified-site                                                   (B) LOCATION: 2                                                               (D) OTHER INFORMATION: (N`- methyl)Arg                                        (ix) FEATURE:                                                                 (A) NAME/KEY: Modified-site                                                   (B) LOCATION: 5                                                               (D) OTHER INFORMATION: Pen-NH2 wherein Pen is                                 penicillamine                                                                 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:                                       CysArgGlyAspXaa                                                               (2) INFORMATION FOR SEQ ID NO:2:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 7 amino acid residues                                             (B) TYPE: Amino Acid                                                          (C) STRANDEDNESS:                                                             (D) TOPOLOGY: Unknown                                                         (ii) MOLECULE TYPE: Peptide                                                   (ix) FEATURE:                                                                 (A) NAME/KEY: Modified-site                                                   (B) LOCATION: 1                                                               (D) OTHER INFORMATION: cyclo (S,S)- N`-acetyl-Cys                             (ix) FEATURE:                                                                 (A) NAME/KEY: Modified-site                                                   (B) LOCATION: 3                                                               (D) OTHER INFORMATION: 4,4'- dimethylthiazolidine-                            5-carboxylic acid                                                             (ix) FEATURE:                                                                 (A) NAME/KEY: Modified-site                                                   (B) LOCATION: 4                                                               (D) OTHER INFORMATION:para- aminomethylphenylalanine                          (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:                                       CysAsnXaaXaaGlyAspCys                                                         5                                                                             (2) INFORMATION FOR SEQ ID NO:3:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 5 amino acid residues                                             (B) TYPE: Amino Acid                                                          (C) STRANDEDNESS:                                                             (D) TOPOLOGY: Unknown                                                         (ii) MOLECULE TYPE: Peptide                                                   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:                                       TyrGlyGlyPheLeu                                                               5                                                                             (2) INFORMATION FOR SEQ ID NO:4:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 5 amino acid residues                                             (B) TYPE: Amino Acid                                                          (C) STRANDEDNESS:                                                             (D) TOPOLOGY: Unknown                                                         (ii) MOLECULE TYPE: Peptide                                                   (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:                                       TyrGlyGlyPheMet                                                               5                                                                             (2) INFORMATION FOR SEQ ID NO:5:                                              (i) SEQUENCE CHARACTERISTICS:                                                 (A) LENGTH: 10 amino acid residues                                            (B) TYPE: Amino Acid                                                          (C) STRANDEDNESS:                                                             (D) TOPOLOGY: Unknown                                                         (ii) MOLECULE TYPE: Peptide                                                   (ix) FEATURE:                                                                 (A) NAME/KEY: Modified-site                                                   (B) LOCATION: 1                                                               (D) OTHER INFORMATION: pyroglutamic acid                                      (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:                                       XaaHisTrpSerTyrGlyLeuArgProGly                                                510                                                                           __________________________________________________________________________

What is claimed is:
 1. A stable, transparent drug delivery compositionsuitable for storage and administration of biologically activematerials, comprising:(a) a delivery composition comprising:(1) fromabout 1 to about 80 weight percent of a pharmaceutically acceptable oilphase; (2) from about 3 to about 98 weight percent surfactant; (3) fromabout 2 to about 60 weight percent polyethylene glycol; (4) from about0.5 to about 15 weight percent water; and (b) a therapeuticallyeffective amount of a biologically active material having anoctanol:water partition coefficient of less than about 0.1;provided thatthe composition does not contain a mixture of cholesterol andphospholipid, and wherein the ratio of the polyethylene glycol to wateris at least 2:1.
 2. The drug delivery composition of claim 1 wherein thedelivery composition further comprises at least one plasticizercomprising sorbitol, mannitol, or glycerin, said plasticizer beingpresent in an amount of from about 0.5 to about 10 weight percent of thedelivery composition.
 3. The drug delivery composition of claim 2wherein the drug delivery composition is contained in a capsule and theratio of the polyethylene glycol to water is from about 4:1 to about99:1, and said plasticizer comprises sorbitol, mannitol, or glycerin. 4.The encapsulated drug delivery composition of claim 3 wherein thecapsule is a gelatin or starch capsule.
 5. The encapsulated drugdelivery composition of claim 4 wherein the active material comprises aprotein, peptide, or polysaccharide.
 6. The encapsulated drug deliverycomposition of claim 5 wherein the surfactant component is a mixture ofsurfactants comprising a low HLB surfactant, said low HLB surfactanthaving an HLB below 10 and a high HLB surfactant, said high HLBsurfactant having an HLB above 10, and wherein the low HLB surfactantcomprises a C₉₋₁₃ monoglyceride.
 7. The encapsulated drug deliverycomposition of claim 5 wherein the active material comprises amedicament which is selected from the group consisting oferythropoietin, insulin, a growth hormone, calcitonin, growth colonystimulating factors, RGD peptides, hematoregulatory peptides,collagenase inhibitors, angiotensin inhibitors, heparins, hypothalamicreleasing peptides, tissue plaminogen activators, artial natriureticpeptides, tumor necrosis factor, vasopressin, a vasopressin antagonist,t-PA, vamprire bat plasminogen amplifier, urokinase, streptokinase,interferon and interleukin, in a biologically effective, therapeutic,non-toxic quantity.
 8. The encapsulated drug delivery composition ofclaim 5 wherein the active material comprises a medicament which isselected from the group consisting of insulins, growth hormones,fibrinogen antagonists and calcitonins.
 9. A stable, transparentdelivery composition, comprising:(a) from about 5 to about 70 weightpercent of a pharmaceutically acceptable oil phase; (b) from about 10 toabout 80 weight percent surfactant; (c) from about 5 to about 60 weightpercent of an aqueous phase comprising from about 60 to about 95 weightpercent polyethylene glycol, from about 2 to about 30 weight percentwater, and from about 1 to about 15 weight percent plasticizercomprising sorbitol, mannitol, glycerin, sucrose, fructose, glucose, orlactose; andwherein the ratio of the polyethylene glycol to water is atleast 2:1, provided that the composition does not contain a mixture ofcholesterol and phospholipid.
 10. The delivery composition of claim 9wherein the polyethylene glycol to water ratio is from about 4:1 toabout 99:1, and said plasticizer comprises sorbitol, mannitol, orglycerin.
 11. The delivery composition of claim 10 wherein the aqueousphase consists of said water, polyethylene glycol, and plasticizer. 12.The delivery composition of claim 11 further comprising atherapeutically effective amount of a biologically active, therapeuticmaterial having an octanol:water partition coefficient of less than 0.1.13. The drug delivery composition of claim 12 wherein the drug deliverycomposition is contained in a hard gelatin, soft gelatin, or starchcapsule.
 14. The encapsulated drug delivery composition of claim 13wherein the biologically active material comprises a protein, peptide,or polysaccharide.
 15. The encapsulated drug delivery composition ofclaim 14 wherein the surfactant component is a mixture of surfactantscomprising a low HLB surfactant, said low HLB surfactant having an HLBbelow 10 and a high HLB surfactant, said high HLB surfactant having anHLB above 10, and wherein the low HLB surfactant comprises a C₉₋₁₃monoglyceride.
 16. The encapsulated drug delivery composition of claim14 wherein the active material comprises a medicament which is selectedfrom the group consisting of erythropoietin, insulin, a growth hormone,calcitonin, growth colony stimulating factors, RGD peptides,hematoregulatory peptides, collagenase inhibitors, angiotensininhibitors, heparins, hypothalamic releasing peptides, tissue plaminogenactivators, artial natriuretic peptides, tumor necrosis factor,vasopressin, a vasopressin antagonist, t-PA, vamprire bat plasminogenamplifier, urokinase, streptokinase, interferon and interleukin, in abiologically effective, therapeutic, non-toxic quantity.
 17. Theencapsulated drug delivery composition of claim 14 wherein the activematerial comprises a medicament which is selected from the groupconsisting of insulins, growth hormones, fibrinogen antagonists andcalcitonins.
 18. The encapsulated drug delivery composition of claim 14wherein the oil is selected from the group consisting of triglycerideshaving from 21 to 45 carbon atoms and propylene glycol diesters havingfrom 15 to 40 carbon atoms.
 19. A method of administering anencapsulated drug delivery composition, comprising:providing a capsulewithin which is contained a drug delivery composition comprising: (a) adelivery composition comprising:(1) from about 5 to about 70 weightpercent of an oil phase; (2) from about 5 to about 60 weight percent ofan aqueous phase consisting essentially of water, polyethylene glycol,and at least one plasticizer, said aqueous phase comprising from about 2to about 30 weight percent water, from about 60 and 95 weight percentpolyethylene glycol, and from about 1 to about 15 weight percentplasticizer comprising sorbitol, mannitol, or glycerin; (3) from about15 to about 75 weight percent of a surfactant mixture; and (b) atherapeutically effective amount of a biologically active therapeuticmaterial having an octanol:water partition coefficient of less thanabout 0.1; and provided that the delivery composition does not contain amixture of cholesterol and phospholipid; andadministering saidencapsulated drug delivery composition either orally, rectally, orvaginally to the body of an animal.
 20. The method of claim 19 whereinsaid active material is either a protein, peptide, or polysaccharide.21. The method of claim 20 wherein said administration is oral.
 22. Themethod of claim 21 wherein the weight ratio of polyethylene glycol towater in said delivery composition is from 4:1 to 99:1.
 23. Theencapsulated drug delivery composition of claim 6 wherein said low HLBsurfactant is present in an amount of from about 10 to about 40 weightpercent of said delivery composition and said high HLB surfactant ispresent in an amount of from about 10 to about 40 weight percent of saiddelivery composition.
 24. The encapsulated drug delivery composition ofclaim 23 wherein said delivery composition comprises from about 15 toabout 55 weight percent polyethylene glycol.
 25. The encapsulated drugdelivery composition of claim 5 wherein said surfactant mixturecomprises from 15 to 75 weight percent of said delivery composition. 26.The encapsulated drug delivery composition of claim 25 provided thatsaid plasticizer does not comprise propylene glycol.
 27. Theencapsulated drug delivery composition of claim 7 provided that saidplasticizer does not comprise propylene glycol.
 28. The encapsulateddrug delivery composition of claim 24 provided that said plasticizerdoes not comprise propylene glycol.
 29. The encapsulated drug deliverycomposition of claim 15 wherein said low HLB surfactant is present in anamount of from about 10 to about 40 weight percent of said deliverycomposition and said high HLB surfactant is present in an amount of fromabout 10 to about 40 weight percent of said delivery composition. 30.The encapsulated drug delivery composition of claim 29 wherein saidaqueous phase comprises from about 70 to about 90 weight percentpolyethylene glycol, and the ratio of the polyethylene glycol to wateris from about 5:1 to about 95:5.
 31. The encapsulated drug deliverycomposition of claim 14 provided that said plasticizer does not comprisepropylene glycol.
 32. The encapsulated drug delivery composition ofclaim 16 provided that said plasticizer does not comprise propyleneglycol.
 33. The encapsulated drug delivery composition of claim 29provided that said plasticizer does not comprise propylene glycol. 34.The method of claim 22 wherein the surfactant component of said deliverycomposition is a mixture of surfactants comprising a low HLB surfactant,said low HLB surfactant having an HLB below 10 and a high HLBsurfactant, said high HLB surfactant having an HLB above 10, and whereinthe low HLB surfactant comprises a C₉₋₁₃ monoglyceride.
 35. The methodof claim 34 wherein said low HLB surfactant is present in an amount offrom about 10 to about 40 weight percent of said delivery compositionand said nigh HLB surfactant is present in an amount of from about 10 toabout 40 weight percent of said delivery composition.
 36. The method ofclaim 35 wherein the active material comprises a medicament which isselected from the group consisting of erythropoietin, insulin, a growthhormone, calcitonin, growth colony stimulating factors, RGD peptides,hematoregulatory peptides, collagenase inhibitors, angiotensininhibitors, heparins, hypothalamic releasing peptides, tissue plaminogenactivators, artial natriuretic peptides, tumor necrosis factor,vasopressin, a vasopressin antagonist, t-PA, vamprire bat plasminogenamplifier, urokinase, streptokinase, interferon and interleukin, in abiologically effective, therapeutic, non-toxic quantity.
 37. The methodof claim 35 wherein the drug delivery composition is contained in a hardgelatin, soft gelatin, or starch capsule.
 38. The method of claim 22provided that said plasticizer does not comprise propylene glycol. 39.The method of claim 35 provided that said plasticizer does not comprisepropylene glycol.
 40. The drug delivery composition of claim 1 whereinthe biologically active material comprises desmopressin.
 41. The drugdelivery composition of claim 3 wherein the biologically active materialcomprises desmopressin.
 42. The drug delivery composition of claim 9wherein the biologically active material comprises desmopressin.
 43. Thedrug delivery composition of claim 10 wherein the biologically activematerial comprises desmopressin.
 44. The method of claim 19 wherein thebiologically active material comprises desmopressin.
 45. The method ofclaim 44 wherein the administration is oral.